Row Pattern, Plant Density, and Nitrogen Rate Effects on Corn Yield in the Southeastern US

Abstract

It is uncertain how corn (Zea mays L.) yield would be affected by planting in a twin-row orientation in the southeastern US. The objectives were to compare corn grain yield when: (i) planted in single and twin rows, (ii) plant densities at recommended (1R) and twice the recommended (2R) rate, and (iii) N rates of 168 and 336 kg/ha. Corn was irrigated using a subsurface drip irrigation system. The single and twin row with 1R seed density had the same corn grain yield (10069 kg/ha), stalk diameter (18.1 mm), and test weight (700 kg/m 3 ). Twinrow 2R had lower grain yield (6967 kg/ha) and smaller stalk diameter (12.8 mm) compared with single- or twin-row 1R. Increased N did not affect grain yield or stalk diameter, but did increase grain test weight. Seed cost for the twin-row R2 was two times that of single- or twin-row R1. Seed cost percentage of gross revenue for single and twin R1 was 8% compared with 30% for twin-row R2. Overall, this research implies corn can be planted in a twin-row pattern without loss of yield or gross revenue provided the plant population does not exceed the recommended rate.